Bee nest?

Bumble bee nests are only active for the summer - in the autumn the new "baby" bumblebee queen bees all jump ship and find somewhere else to live. So you're excuse to leave that part of the garden untended will expire in a very few weeks time. Boo!

Hello, we had one and apparently they should be left alone, they are only usually around for a couple of months then they naturally just shut down and empty. They are very good for the garden, and quite special really!

I think you're supposed to leave it well alone, including the surrounding greenery. Because the bees use it as a reference so they can find their way home. Sorry not to be more help, I'm not sure how long they stick around for. I'd be quite pleased myself!